Sensors are the essential devices to industrial applications, particularly for chemical industries where varieties of sensors are being used for different applications.

The chemical industry is a major player in the global economy. Typically, strict limits and quotas are set for the emission levels of different substances, and record keeping and monitoring by the appropriate regulatory authority is put in place to ensure that the limits are observed.

The gas sensing industry plays the key role in enabling the industry to meet its obligations, with many different technologies used to monitor the emissions from the different parts of a typical chemical plant.

Flue gas analyzers are portable / transportable instruments that are used to take spot measurements of a range of gases including oxygen, carbon monoxide, carbon dioxide, SOx and NOx in the flue gases, thereby monitoring the efficiency of the burning process and taking a reading for emission control purposes. They will normally be fitted with electrochemical sensors, which are arguably the most versatile sensors available. The sensors are physically small, enabling the analyzers themselves to be correspondingly compact.
Electrochemical sensors characterized to a large number of different gases are available, enabling monitoring in specialized applications to be implemented quickly and easily.

For flammable gases, pellistors/catalytic are widely used. This sensor works by burning the target gas; the heat generated producing a change in the resistance of the detecting element of the sensor proportional to the gas concentration. To detect hydrocarbons, NDIR sensors are widely used.